Phd in INFORMATION AND COMMUNICATION TECHNOLOGY (ICT)

Thesis title: Characterization of (3200) Phaethon asteroid by ground based telescopes and laboratory experiment in support to DESTINY+ space mission

The exploration of asteroids is crucial for understanding the early evolution of the solar system, as they contain remnants of the primordial solar nebula from which the planets formed. Among these, near-Earth asteroids (NEAs) hold significant interest due to their collision risk with Earth and their accessibility for scientific investigation. The upcoming JAXA mission, DESTINY+ (Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science), aims to perform a flyby of NEA asteroid (3200) Phaethon, an object classified as an 'active asteroid' due to its transient comet-like activity near perihelion (0.14 AU ). Equipped with two cameras and a dust analyser, DESTINY+ aims to study Phaethon’s surface morphology, composition, and dust environment. This dissertation investigates Phaethon's surface by analysing visible and near-infrared (VIS-NIR) ground-based observations collected over the past two decades. Specifically, it examines the effects of extreme perihelion temperatures on potential surface changes and explores the relationship between Phaethon’s surface composition and meteorites, the only extraterrestrial materials available for study on Earth. To simulate perihelion conditions, an experimental setup was also developed to heat meteorites in a vacuum at high temperatures. Spectroscopic and mineralogical analyses of the samples post-heating reveal potential alteration patterns, offering insights into asteroid surface evolution. The findings support the DESTINY+ mission by providing valuable data on Phaethon’s surface characteristics. This research contributes to our understanding of asteroid evolution, particularly concerning surface modifications near the Sun, and lays critical groundwork for interpreting data collected during the upcoming DESTINY+ flyby. This dissertation is structured as follows: • Chapter 1 introduces asteroids, including their distribution, taxonomy, and connections to meteorites. • Chapter 2 is into the nature of 'active asteroids,' a class to which (3200) Phaethon belongs, exploring their unique characteristics and activity mechanisms. • Chapter 3 develops a new thermal model for (3200) Phaethon at perihelion, estimating surface temperatures and examining potential thermally induced changes. • Chapter 4 analyses VIS-NIR ground-based observations collected over two decades to investigate Phaethon’s spectral properties and its compositional linkages to meteorites. • Chapter 5 describes the experimental simulation of perihelion conditions, where meteorite samples were subjected to high-temperature vacuum heating, followed by spectroscopic and mineralogical analysis to detect alteration. • Chapter 6 concludes with a discussion of key findings and the prospects for DESTINY+ mission.